1. Field of the Invention
The invention relates to a self-closing valve for sanitary installations and, more particularly, to an improved valve assembly which will automatically close after a predetermined time has elapsed.
2. Description of the Prior Art
Self-closing valves of the type having a reciprocating handle with which the valve is opened and when released, after partial discharge of the back pressure chamber, and with the assistance of the valve spring, the valve returns to its closed position.
One of the advantages of using self-closing valves is that the quantity of water released upon actuation can be proportioned by a one-time adjustment when the assembly is installed so that water conservation is optimized. Self-closing valves are used primarily in public installations, such as baths, toilets and like sanitary facilities in institutional buildings, railroad stations, airports and the like. It is in the interest of water economy and conservation of water use to provide a self-closing valve to pre-select the quantity of water to be discharged. Other types of fittings with self-closing action are universally known, such as pushbutton or lever-actuated fittings for flushing toilets or urinals.
German Utility Design No. 8,018,314 discloses a self-closing valve for a water fixture. The valve includes a cup cylinder that seals a back pressure or metering chamber and caps the piston. When the valve is opened, a handle travels a preset stroke distance to discharge water from the metering chamber; then the metering chamber automatically fills when the handle returns to its closed position. The handle is of the rotary type and, when rotated, alters the setting of the cup cylinder axially relative to the plunger.
A disadvantage of this type of valve is that the main valve seal must be forced upon the valve seat against the inlet pressure of the water, which requires a high actuating force, to shift the handle to and from its closed to its opened positions. Another disadvantage is that needle protrudes into its passageway in the plunger and determines the least port area for filling the metering chamber. Such an arrangement is easily clogged by dirt particles.